1. Field of the Invention
This invention is directed to methods and apparatuses for treating snoring. More particularly, this invention is directed to a delivery system for such a method and apparatus.
2. Description of the Prior Art
Snoring has received increased scientific and academic attention. One publication estimates that up to 20% of the adult population snores habitually. Huang, et al., xe2x80x9cBiomechanics of Snoringxe2x80x9d, Endeavour, p. 96-100, Vol. 19, No. 3 (1995). Snoring can be a serious cause of marital discord. In addition, snoring can present a serious health risk to the snorer. In 10% of habitual snorers, collapse of the airway during sleep can lead to obstructive sleep apnea syndrome. Id.
Notwithstanding numerous efforts to address snoring, effective treatment of snoring has been elusive. Such treatment may include mouth guards or other appliances worn by the snorer during sleep. However, patients find such appliances uncomfortable and frequently discontinue use (presumably adding to marital stress).
Electrical stimulation of the soft palate has been suggested to treat snoring and obstructive sleep apnea. See, e.g., Schwartz, et al., xe2x80x9cEffects of electrical stimulation to the soft palate on snoring and obstructive sleep apneaxe2x80x9d, J. Prosthetic Dentistry, pp. 273-281 (1996). Devices to apply such stimulation are described in U.S. Pat. Nos. 5,284,161 and 5,792,067. Such devices are appliances requiring patient adherence to a regimen of use as well as subjecting the patient to discomfort during sleep. Electrical stimulation to treat sleep apnea is discussed in Wiltfang, et al., xe2x80x9cFirst results on daytime submandibular electrostimulation of suprahyoidal muscles to prevent night-time hypopharyngeal collapse in obstructive sleep apnea syndromexe2x80x9d, International Journal of Oral and Maxillofacial Surgery, pp. 21-25 (1999).
Surgical treatments have been employed. One such treatment is uvulopalatopharyngoplasty. In this procedure, so-called laser ablation is used to remove about 2 cm of the trailing edge of the soft palate thereby reducing the soft palate""s ability to flutter between the tongue and the pharyngeal wall of the throat. The procedure is frequently effective to abate snoring but is painful and frequently results in undesirable side effects. Namely, removal of the soft palate trailing edge comprises the soft palate""s ability to seal off nasal passages during swallowing and speech. In an estimated 25% of uvulopalatopharyngoplasty patients, fluid escapes from the mouth into the nose while drinking. Huang, et al., supra at 99. Uvulopalatopharyngoplasty (UPPP) is also described in Harries, et al., xe2x80x9cThe Surgical treatment of snoringxe2x80x9d, Journal of Laryngology and Otology, pp. 1105-1106 (1996) which describes removal of up to 1.5 cm of the soft palate. Assessment of snoring treatment is discussed in Cole, et al., xe2x80x9cSnoring: A review and a Reassessmentxe2x80x9d, Journal of Otolaryngolomy, pp. 303-306 (1995).
Huang, et al., supra, describe the soft palate and palatal snoring as an oscillating system which responds to airflow over the soft palate. Resulting flutter of the soft palate (rapidly opening and closing air passages) is a dynamic response generating sounds associated with snoring. Huang, et al., propose an alternative to uvulopalatopharyngoplasty. The proposal includes using a surgical laser to create scar tissue on the surface of the soft palate. The scar is to reduce flexibility of the soft palate to reduce palatal flutter. Huang, et al., report initial results of complete or near-complete reduction in snoring and reduced side effects.
Surgical procedures such as uvulopalatopharyngoplasty and those proposed by Huang, et al., continue to have problems. The area of surgical treatment (i.e., removal of palatal tissue or scarring of palatal tissue) may be more than is necessary to treat the patient""s condition. Surgical lasers are expensive. The proposed procedures are painful with drawn out and uncomfortable healing periods. The procedures have complications and side effects and variable efficacy (e.g., Huang, et al., report promising results in 75% of patients suggesting a full quarter of patients are not effectively treated after painful surgery). The procedures may involve lasting discomfort. For example, scar tissue on the soft palate may present a continuing irritant to the patient. Importantly, the procedures are not reversible in the event they happen to induce adverse side effects not justified by the benefits of the surgery.
According to a preferred embodiment of the present invention, a delivery system is disclosed for delivering an implant into a soft palate of a patient for treatment of snoring. The system includes an implant and a delivery tool. The implant is formed from a sheet of flexible, bio-compatible material having a longitudinal length between a proximal edge and a distal edge, a transverse width and a thickness between upper and lower surfaces. The material is sized to be inserted into the soft palate with the longitudinal length extending aligned with an anterior-posterior axis of the palate and with the thickness contained within a thickness of the soft palate. The delivery tool includes a penetrating member with a distal end for penetration into the soft palate through a small penetration wound. The implant is carried in the distal end of the penetrating member with the longitudinal dimension of the implant aligned with an axis of the penetration member. A flattening tool is contained within the penetration member and constrained by the penetration member against a bias for a distal tip of the tool to expand beyond a size of the penetration wound to approximately a width of the implant. The flattening tool is retractable between an extended position and a retracted position with the distal tip of the tool in the retracted position being smaller than the penetration wound. The penetration member is retractable relative to the flattening tool when the flattening tool is in the extended position.